KR101002308B1 - Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a liquid crystal display device in which a touch panel is formed on one surface of a cover glass to reduce the number of processes and facilitates assembly, and a display area is defined at the center thereof and a non-display area is defined at the outside thereof. A liquid crystal panel comprising an opposing first substrate, a second substrate, and a liquid crystal layer formed between the first and second substrates, and formed on the liquid crystal panel and being transparent to a surface facing the liquid crystal panel; A cover glass having a touch sensing unit including a plurality of first and second electrodes crossing each other perpendicularly to each other, and a touch formed on one side of the cover glass deviating from the display area of the liquid crystal panel on the same surface as the touch sensing unit. And a panel signal applying unit.

Touch panel, capacitive method

Description

Liquid Crystal Display Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which a touch panel is formed on one surface of a cover glass to reduce the number of steps and facilitate assembly.

In recent years, as the information age has entered, the display field for visually expressing electrical information signals has been rapidly developed, and various flat panel display devices having excellent performance of thinning, light weight, and low power consumption have been developed. Flat Display Device has been developed and is rapidly replacing the existing Cathode Ray Tube (CRT).

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display device. (Electro luminescence Display Device: ELD) and the like, these are commonly used as an essential component of a flat panel display panel that implements an image, a flat panel display panel has a pair of light emitting or polarizing material layer in between It has a configuration in which a transparent insulating substrate is faced and bonded together.

The dual liquid crystal display displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the image display device includes a display panel having a liquid crystal cell, a backlight unit for irradiating light to the display panel, and a driving circuit for driving the liquid crystal cell.

The display panel is formed such that a plurality of unit pixel regions are defined by crossing a plurality of gate lines and a plurality of data lines. In this case, each pixel area includes a thin film transistor array substrate and a color filter array substrate facing each other, a spacer positioned to maintain a constant cell gap between the two substrates, and a liquid crystal filled in the cell gap.

The thin film transistor array substrate includes a gate line and a data line, a thin film transistor formed of a switch element at each intersection of the gate lines and the data lines, a pixel electrode formed of a liquid crystal cell and connected to the thin film transistor, and the like. It consists of the applied alignment film. The gate lines and the data lines receive signals from the driving circuits through the respective pad parts.

The thin film transistor supplies the pixel voltage signal supplied to the data line to the pixel electrode in response to the scan signal supplied to the gate line.

The color filter array substrate includes color filters formed in units of liquid crystal cells, a black matrix for distinguishing between color filters and reflecting external light, a common electrode for supplying a reference voltage to the liquid crystal cells in common, and an alignment layer applied thereon. It consists of.

The thin film transistor substrate and the color filter array substrate manufactured as described above are aligned and bonded to each other, and then liquid crystal is injected and encapsulated.

As described above, there is an increasing demand for a liquid crystal display device having a touch panel capable of recognizing a touch portion through a hand of a person or a separate input means and transmitting separate information corresponding thereto. Currently, such a touch panel is applied in the form of attaching to an outer surface of a liquid crystal display.

Hereinafter, a conventional touch panel type liquid crystal display device will be described with reference to the accompanying drawings.

1 is a schematic view showing a typical touch panel attached liquid crystal display device.

As shown in FIG. 1, a general touch panel type liquid crystal display device includes first and second substrates 1 and 2 facing each other, a liquid crystal layer 3 filled therebetween, and a first substrate 1 and A liquid crystal panel 10 including first and second polarizing plates 4a and 4b attached to each of the rear surfaces of the second substrate 2, and disposed on the liquid crystal panel 10, and having an electrostatic capacitance therein. A touch panel 20 driven in a capacitive manner and a cover glass 30 protecting the upper portion of the touch panel 20 are included.

Here, on the first substrate 1 of the liquid crystal panel 10, a gate line and a data line Data that cross each other and define a pixel area are formed at an intersection of the gate line and the data line. A thin film transistor TFT and a thin film transistor array having pixel electrodes (not shown) are formed in the pixel region.

Further, on the second substrate 2, a black matrix layer, a color filter layer and a common electrode (not shown, Vcom (applied voltage)) are formed.

Here, the touch panel 20 has an internal structure different according to its method. For example, a method of sensing a touch by changing a capacitance at a touch point is called a capacitive method. The first and second electrodes are formed, and sensing is performed by a change in capacitance value formed between these electrodes.

In addition, in order to protect the touch panel 20, a cover glass 30 is further formed on the touch panel.

In the above-described conventional touch panel type liquid crystal display device, an adhesive layer is required between the touch panel 20 and the liquid crystal panel 10. In this case, a process of forming the touch panel 20 is required separately from the liquid crystal panel 10, and a process of attaching the touch panel 20 and the liquid crystal panel 10 is required.

The conventional touch panel type liquid crystal display device has the following problems.

The touch panel is formed in an external form of the liquid crystal panel together with a cover glass protecting the same, and an adhesive layer is required between the touch panel and the liquid crystal panel. In this case, a separate attachment process is required, and in addition, when the touch panel and the liquid crystal panel are misaligned, it is difficult to separate them again after being attached, and even if they are separated, damage to the touch panel may occur.

In addition, an increase in the number of processes may occur due to the adhesion process of the adhesive layer between the touch panel and the liquid crystal panel.

An object of the present invention is to provide a liquid crystal display device which is designed to solve the above problems and is formed on one surface of a cover glass to reduce the number of steps and facilitate assembly.

The liquid crystal display device of the present invention for achieving the above object, the first substrate, the second substrate and the first substrate facing each other, the display area is defined in the center, the non-display area is defined on the outside And a plurality of first and second electrodes formed on the liquid crystal panel, the liquid crystal panel including a liquid crystal layer formed between the second substrates, and transparent and vertically intersecting with each other on a surface opposite the liquid crystal panel. A cover glass having a touch sensing unit including a touch panel and a touch panel signal applying unit formed on the same surface as the touch sensing unit are included on one side of the cover glass which is deviated from the display area of the liquid crystal panel.

The cover glass protrudes from the liquid crystal panel, and the touch panel signal applying unit is formed in an area of the cover glass protruding from the liquid crystal panel.

Here, the first electrode is formed of a rod-shaped electrode long in the X-axis direction, and the second electrode is an electrode formed of a long rod-shaped intersecting the X electrode and in the Y-axis direction. The first electrode and the second electrode are formed on different layers, and a transparent insulating film is further formed between the layers of the first electrode and the second electrode. Here, the transparent insulating film is formed to a thickness of 0.1 ~ 5㎛.

Alternatively, the plurality of first electrodes and the second electrode are formed spaced apart from each other on the cover glass, the first electrode is formed by dividing a plurality of islands in a column in the horizontal direction, respectively, and the second electrode in the vertical direction It is formed in the shape of a rod in one direction in rows. A first electrode signal application wiring for applying a signal to the first electrodes formed in each column in the horizontal direction is further formed on the upper side or the lower side of the first electrode via a transparent insulating film. It is electrically connected to the one electrode through the contact hole.

The liquid crystal panel includes a thin film transistor array including a gate line and a data line crossing each other on the first substrate to define a pixel region, and a pixel electrode formed in the pixel region, and except for the pixel region on the second substrate. And a color filter array including a black matrix layer corresponding to an area and a color filter layer corresponding to the pixel area. The first electrode signal application wiring is formed in a portion where an image is not displayed in the liquid crystal panel so as not to interfere with an image. For example, it may be formed corresponding to the black matrix layer.

The first electrode and the second electrode are made of any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO).

The touch panel signal controller is made of FPC (Flexible Printed CAble), and is folded below the liquid crystal panel.

A voltage applying pad configured to apply a voltage signal to the first electrode on the cover glass corresponding to the touch panel signal controller, the first electrode and the second electrode of the touch sensing unit being connected through a connection line; And a voltage detecting pad detecting a signal output from the second electrode, wherein the voltage applying pad and the voltage detecting pad are connected to the touch panel signal controller by soldering.

The liquid crystal display of the present invention as described above has the following effects.

In the case of mobile devices such as mobile phones and PMPs, in which liquid crystal panels are used, slimming is required due to the characteristics of the use environment. When the touch panel is implemented by the capacitive type, the thickness of the entire module is determined at least by a thickness of the sum of the cover glass, the liquid crystal module, the touch panel, and the polarizer. However, the liquid crystal display of the present invention omits an additional touch panel, and constitutes an insulating film between the X electrode and the Y electrode on the cover glass side, and additionally does not include the touch panel, and performs an array process on the cover glass. Proceeding to form a touch glass integrated cover glass, and attach it to the liquid crystal panel to integrate.

That is, the liquid crystal display of the present invention does not separately form the touch panel, and detects the touch sensing unit on the inner surface of the cover glass which is formed to protect the touch panel, thereby reducing the module thickness of the entire liquid crystal display. It provides a way to reduce costs by eliminating the touch panel adhesion process.

Therefore, the adhesive layer required in the formation of the additional touch panel or the process of attaching the touch panel and the liquid crystal panel is omitted, and the damage rate of the touch panel or the like is prevented during the misalignment, thereby lowering the defective rate to form the liquid crystal panel of the touch panel type. This is possible. As a result, the omission of the attachment process can reduce the process cost and process time, and thus can be expected to improve the yield.

Hereinafter, a liquid crystal display and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a plan view illustrating the inside of a cover glass of the liquid crystal display of the present invention, and FIG. 3 is a cross-sectional view of the structure of the liquid crystal display device corresponding to the line II ′ of FIG. 2 of the present invention.

2 and 3, the liquid crystal display of the present invention includes an X electrode 210, a Y electrode 212, and an X electrode 210 before Y for touch detection inside the cover glass 200. The insulating film 211 between the poles 212 is constituted. That is, the touch glass is provided in the form of an array inside the cover glass 200 provided to prevent damage to the touch panel due to pressure and external stimulus without providing a separate touch panel, and the cover glass integrated touch panel ( 2000 and the liquid crystal panel 100 are bonded to each other by the adhesive layer 220.

More specifically, in the liquid crystal display of the present invention, the liquid crystal panel 100 includes the first and second substrates 110 and 120 facing each other and the liquid crystal layer 130 filled therebetween. The first polarizing plate 140a and the second polarizing plate 140b are formed on the rear surfaces of the first and second substrates 110 and 120, respectively.

Although not shown in detail, a thin film transistor array including a gate line and a data line and a pixel electrode formed in the pixel region are formed on the first substrate 110 to cross each other. A color filter array including a black matrix layer, a color filter layer, and a common electrode is formed on the second substrate 120.

In this case, as described above, the common electrode may be formed on the entire surface of the second substrate, and in some cases, the common electrode may be formed in the pixel area on the first substrate 110 in an alternating shape with the pixel electrode. . Which common electrode shape is adopted depends on the mode required for the liquid crystal panel (TN (Twisted Nematic) mode and IPS (In-Plane Switching) mode).

In addition, one side of the cover glass 200 is formed slightly longer than the liquid crystal panel 100 to define a pad part inside the protruding region. In the pad part, a plurality of pads 242 are formed to apply signals to the X electrode 210 and the Y electrode 212, respectively, and the plurality of pads 242 are the respective X electrodes 210 and Y. The connection line 252 is connected to the electrode 212.

In addition, the plurality of pads 242 are connected to the touch panel signal applying unit 300 made of a flexible flexible printed cable (FPC) by soldering.

4 is an enlarged plan view illustrating an intersection of an X electrode and a Y electrode in the liquid crystal display of the present invention.

Looking at the enlarged intersection of the X electrode 210 and the Y electrode 212 shown in FIG. 4, the width of the X electrode 210 is not reduced to be formed at the portion overlapping with the Y electrode 212. Can be.

In the liquid crystal display of the present invention, a capacitance change between the X electrode 210 and the Y electrode 212 is detected at a touch point in a capacitive manner to grasp the touch position. In this case, when the area of the intersection between the X electrode 210 and the Y electrode 212 is large, the load may increase at this region, and thus it may be difficult to detect the change in capacitance. In order to prevent this, the width of the X electrode 210 is selectively reduced at the intersection of the X electrode 210 and the Y electrode 212. In the illustrated example, the width of the X electrode 210 is given, but in some cases, the width of the Y electrode 212 may be reduced, or the width of both electrodes may be reduced.

5 is a plan view showing a modification of the shape of the X electrode and the Y electrode in the liquid crystal display device of the present invention.

FIG. 5 shows, as a variant, an uniform area of the X electrode 310 and the Y electrode 312, and at the intersection of the X electrode 310 and the Y electrode 312, respectively, the X electrode 310 and the Y electrode 312. By reducing the width of the electrode 312 to reduce the area at the intersection portion is a structure that at least prevents the load that may occur when capacitive detection. In the illustrated structure, each of the X electrode 310 and the Y electrode 312 is shown in a rhombus, but in addition, the area occupied by the X electrode 310 and the Y electrode 312 on the cover glass 200 can be uniformly represented. If so, it can be modified in other forms.

6 is a plan view illustrating a state in which a cover glass and a liquid crystal panel are attached and a touch signal applying unit and an image signal detecting unit are connected to each other in the liquid crystal display of the present invention.

As shown in FIG. 6, in the liquid crystal display of the present invention, the cover glass 200 is attached to the liquid crystal panel 100 formed by bonding the first and second substrates 110 and 120 to each other via a liquid crystal layer (not shown). It adheres through the adhesive layer (refer 220 of FIG. 3).

Here, referring to the liquid crystal panel 100, the first substrate 110 is formed to protrude relative to the second substrate 120. When the protruding region is defined as a first region, pad electrodes (not illustrated) for applying signals to a gate line (not shown) and a data line (not shown) formed on the first substrate 110 in the first region. The pad electrodes are connected to the respective gate lines and the data lines, and the pad electrodes are also connected to the external image signal applying unit 150 by soldering or the like. In the drawing, pad electrodes of the gate line and the data line are formed on one side of the liquid crystal panel 100 (first area: defined on the lower side in the drawing). In this case, the gate lines are bypassed through the vertical connection line and the horizontal connection line connected to both sides of the gate lines, and are connected to each pad electrode.

On the other hand, an area in which display is displayed in the center of the overlapping areas of the first and second substrates 110 and 120 is called an active area AA.

The cover glass 200 has a second area protruding from the liquid crystal panel 100, and a pad electrode for applying a signal to the X electrode and the Y electrode in the second area of the cover glass 200. C) and a touch panel signal applying unit 300 connected by soldering.

As described above, the cover glass 200 is described to have a second area that does not overlap the liquid crystal panel 100 for the connection of the touch panel signal applying unit 300. It may also be considered to minimize the second area protruding from the liquid crystal panel 100 by allowing the pad electrode formation portion to enter the outer portion of the active area AA of the liquid crystal panel 100.

Here, the image signal applying unit 150 and the touch panel signal applying unit 300 are each made of a flexible FPC (Flexible Printed Cable), which are folded to the lower side of the liquid crystal panel 100 when assembled to the liquid crystal module. .

In the following, an example in which the protruding second region of the cover glass 200 of the above-described form is disposed differently will be described.

7A to 7C are plan views illustrating another example of a method for connecting a touch signal applying unit of the liquid crystal display of the present invention.

FIG. 7A illustrates a state in which the touch sensing unit formed in the cover glass 200 and the touch panel signal applying unit 300 are connected from the lower side, and FIG. 7B illustrates the touch sensing unit formed in the cover glass 200 and the touch panel signal. In the state in which the applying unit 300 is connected at the left side, in FIG. 7C, the touch sensing unit and the touch panel signal applying unit 300 formed at the cover glass 200 are connected at the right side, respectively, so that the connection portions are different.

In FIG. 7A, the touch panel signal applying unit 300 and the image signal applying unit 150 for applying an image signal to the liquid crystal panel 100 partially overlap each other, but the wirings of the respective applying units 300 and 150 overlap. There is no danger of short circuit between the metal wires because they are located on the opposite side rather than on opposite sides. That is, in FIG. 7A, the touch panel signal applying unit 300 connected to the cover glass 200 includes metal wires connected to soldering to pad electrodes formed on the inner surface of the cover glass 200. The metal wire is positioned on a side of the surface of the drawing, and the image signal applying unit 150 connected to the liquid crystal panel 100 is connected to each gate line pad electrode and data line pad electrode of the liquid crystal panel 100. The metal wirings are positioned on the rear surface of the image signal applying unit 150 (corresponding to the back side of the drawing), and the metal wirings of the touch panel signal applying unit 300 and the image signal applying unit 150 are positioned. There is no risk of short, as its forming surface is reversed.

In the case of the structure of FIG. 7A, the protruding region from the liquid crystal panel 100 may be minimized or omitted from the standpoint of the cover glass 200, which is advantageous for integration. However, since the position of the touch panel signal applying unit 150 may be limited in consideration of a relationship with a light source or a circuit board positioned below the liquid crystal panel 100, both the configuration of the lower components and the advantages of optimization are considered. To determine the position of the touch panel signal applying unit 150.

7B and 7C show the touch panel signal applying unit 150 corresponding to the left side or the right side of the liquid crystal panel 100. The structures of FIGS. 6, 7B, and 7C may take the structure of FIG. 7A in some cases. In this case, it may be selectively selected in order to prevent a problem in which electrical interference between the image signal applying unit 150 and the touch panel signal applying unit 300 occurs.

Hereinafter, an example in which a structure in which the intersection between the X electrode and the Y electrode is minimized will be described in consideration of an error in touch sensing when the load generated at the intersection between the X electrode and the Y electrode is large.

8A and 8B are a plan view and a cross-sectional view showing an example in which the X electrode and the Y electrode are disposed on the same layer in the liquid crystal display device of the present invention.

In the embodiment shown in FIG. 8A, the X electrodes 411 of each column in the X-axis direction are linearly formed on each X axis (horizontal line) without forming the X electrodes and the Y electrodes of FIGS. A plurality of spaced apart electrodes are formed, and a bar-shaped Y electrode 412 is formed to pass in the Y-axis direction between the spaced X electrodes 411.

The X electrode 411 and the Y electrode 412 are formed on the same layer as one of transparent electrodes of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO).

The Y electrode 412 extends in the Y-axis direction and includes a pad electrode at one side thereof.

As shown in FIG. 8B, the X electrodes 411 of each column are formed across the X electrodes 411 of each column spaced apart from each other by the X electrode signal application wiring 421 through the transparent insulating film 413. The X electrode signal application wiring 421 is electrically connected to the X electrode 411 by contact holes 421a and 421b formed in each transparent insulating layer 413.

The X electrode signal application wiring 421 is formed for each column in which the X electrodes 411 are formed, and each X electrode signal application wiring 421 is connected through one pad electrode 431 and a pad contact hole 433. do.

Here, the X electrode signal application wiring 421 is made of a metal, and positions corresponding to the black matrix layer formed on the second substrate 120 of the liquid crystal panel 100 in order to prevent a decrease in the aperture ratio. To form.

9A and 9B are a plan view and a cross-sectional view showing a modification in which the X electrode and the Y electrode are arranged on the same layer in the liquid crystal display device of the present invention.

9A and 9B illustrate the X electrode 521 and the Y electrode 523 in which the X electrode signal application wiring 511 is made of a transparent electrode in comparison with the structures of FIGS. 8A and 8B in the liquid crystal display of the present invention. ), A transparent insulating film 512 is formed on the X electrode signal application wiring 511, and an X electrode 521 and a Y electrode 523 spaced apart from each other are formed on the transparent insulating film. do. In this case, the shape of the X electrode 521 and the Y electrode 523 in the plane is the same as in Fig. 8A, and only the positional relationship is reversed.

Here, the X electrode 521 of each column is electrically connected through the X electrode signal application wiring 511 formed below and the contact holes 522a and 522b formed in the transparent insulating film 512, and the X electrode signal applied. A pad electrode 525 formed of a transparent electrode on the same layer as the X electrode 521 is further formed to overlap one side of the wiring 511, and the pad electrode 525 is formed on the lower X electrode signal application wiring 511. It is electrically connected to one side through the pad contact hole 522c.

In FIGS. 8A and 9A, the X electrodes are island-shaped and the Y electrodes are formed in the shape of rods. However, both the X electrodes and the Y electrodes may be formed in a rhombus shape.

9C is a plan view and a cross-sectional view showing an example in which the arrangements of the lozenge X and Y electrodes are applied to the same layer in the method of FIGS. 9A and 9B.

Referring to FIG. 9C, the first electrodes 321 are arranged to be spaced apart in rows in a horizontal direction on a rhombic island, and a plurality of these columns are formed, and the second electrodes 322 are arranged in rows in each vertical direction without interruption. It can be seen that it is thermally connected and maintains a lozenge at adjacent portions of each of the first electrodes 321 and is connected at a small width at the intersection thereof.

The first electrode 321 and the second electrode 322 are formed of a transparent electrode of the same layer. As described above, the second electrode 322 has a pad electrode on its own side and has a signal. And a first electrode signal applying line 320 on each horizontal column to electrically connect the first electrodes 321 spaced apart from each other and electrically connect them to each other on each column. As described above, the first electrode signal applying line 320 may be positioned on the upper side or the lower side of the first electrode 321 / the second electrode 322 via a transparent insulating layer. A contact hole 325 is formed in each of the first electrode 321 and the first electrode signal application line 320.

FIG. 10 is a graph illustrating a change in capacitance between an X electrode and a Y electrode according to an insulating film thickness between two electrodes. FIG.

FIG. 10 illustrates capacitance capacitance values varying with respect to the thickness of the first insulating film between the X electrode and the Y electrode. As the thickness of the first insulating film becomes thicker, it is observed that there is no difference between when there is no touch and when there is touch. When the thickness of the first insulating film is too thick, the thickness of the first insulating film is determined in a range before the inversion phenomenon in which the capacitance increases when there is no touch than when there is a touch.

Experimentally, considering the wiring resistance of each X electrode and Y electrode, and the capacitance value at the intersection thereof, the value is about 50 femto F or more, and the touch value is different between the touch time and the meter measurement time. Sensing was possible. Looking at the numerical value in the graph, it can be seen that the capacitance detection is effective when the thickness of the transparent insulating film between the X electrode and the Y electrode has a thickness of about 42㎛ or less.

However, when applied to a product, it is necessary to consider slimming, and it is possible to identify whether the touch is possible when the capacitance change before and after the touch is a predetermined value or more. Is set in the range of 0.1-5 micrometers.

In this case, the insulating film between the X electrode and the Y electrode may be an organic insulating film such as photoacryl or BCB (Benzo Cyclo Butene), or an inorganic insulating film of a gate insulating film or a nitride film may be used.

In the above-described liquid crystal display device of the present invention, the liquid crystal panel 100 will be described with reference to FIG. 2.

The first substrate 110, the second substrate 120, a thin film transistor array (not shown) formed on the first substrate 110, and the second substrate 120 are formed to face each other. A color filter array (not shown), a liquid crystal layer 130 filled between the thin film transistor array and the color filter array, and a first polarizing plate 140a formed on the back surface of the first substrate 110 and the second substrate 12, respectively. ) And the second polarizing plate 140b.

The thin film transistor array formed on the first substrate 110 may include a plurality of gate lines (not shown), data lines (not shown), and pixel electrodes formed on the pixel areas crossing each other to define a pixel area. And a thin film transistor (not shown) formed at the intersection of the gate line and the data line.

The color filter array substrate 120 formed on the second substrate 120 includes a black matrix layer (not shown), a color filter layer (not shown), and an overcoat layer (not shown) formed on the second substrate 120. And a common electrode (not shown) formed on the entire surface of the overcoat layer.

In the above-described liquid crystal display device of the present invention, the touch sensing unit formed on the cover glass 200 is capable of multi-touch, and applies a voltage to the X electrodes in each horizontal row in turn, from the Y electrodes in the vertical row. By detecting the current value, whether the touch is detected by the change in the detected current value. In this case, the X electrode and the Y electrode may be formed in a different order from each other, or the current sensing according to the voltage application may be exchanged with each other.

The liquid crystal display of the present invention does not form a touch panel separately, but detects a touch sensing unit on an inner surface of a cover glass which is formed for protection of the touch panel, thereby making a thin module thickness of the entire liquid crystal display and touching it. It provides a way to reduce costs by eliminating the adhesive process of panels.

The driving method for extracting the presence or absence of touch is as follows.

First, the voltage is applied to the driving X electrode (or the first electrode) in a pulse form, and the X electrode (or the first electrode) is sequentially scanned. When a voltage is applied to the X electrode (or the first electrode) in the form of a pulse, a change in the amount of charge occurs in the capacitor between the Y electrode (or the second electrode) and the X electrode (the first electrode) due to the voltage variation. The amount of charge variation is measured on the Y electrode (or second electrode) side, and the amount of charge variation also varies because the capacitance between the X electrode (first electrode) and the Y electrode (second electrode) varies depending on the presence or absence of a touch. do. Therefore, by detecting the difference in the amount of charge that varies depending on the presence or absence of the touch it is determined whether the touch.

In the liquid crystal display of the present invention, since a touch sensing unit including an X electrode and a Y electrode is formed in the cover glass, the touch glass is touched, and then the touch sensing unit detects whether the touch panel is mounted, the externally mounted touch panel is compared with the conventional structure. It can omit, In the liquid crystal display device with a touch panel, a thinner module can be manufactured as a whole. In addition, the process may be simplified by placing electrodes on one surface of the cover glass, thereby reducing the degree of misalignment between the X electrode and the Y electrode, and using a pad electrode as the touch sensing unit (the X electrode or the Y electrode). Is formed on one side of the cover glass, which is advantageous in bonding surfaces such as FPC of the touch panel signal applying unit. In addition, since the touch panel, which is separately configured, is integrated and formed in the cover glass, the use of the glass used for the touch panel is omitted, and there is no adhesion process between the glass for the touch panel and the cover glass. It can reduce the cost.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

1 is a schematic view showing a typical touch panel attached liquid crystal display device

2 is a plan view showing the inside of the cover glass of the liquid crystal display of the present invention.

3 is a cross-sectional view of a structure of a liquid crystal display device corresponding to a line I-I 'of FIG. 2 of the present invention.

4 is an enlarged plan view illustrating an intersection of an X electrode and a Y electrode in the liquid crystal display of the present invention.

5 is a plan view showing a modification of the shape of the X electrode and the Y electrode in the liquid crystal display device of the present invention.

6 is a plan view illustrating a state in which a cover glass and a liquid crystal panel are attached and a touch signal applying unit and an image signal detecting unit are connected to each other in the liquid crystal display of the present invention.

7A to 7C are plan views illustrating another example of the method for connecting the touch signal applying unit of the liquid crystal display of the present invention.

8A and 8B are a plan view and a cross-sectional view showing an example in which the X electrode and the Y electrode are disposed on the same layer in the liquid crystal display device of the present invention.

9A and 9B are a plan view and a cross-sectional view showing a modification in which the X electrode and the Y electrode are arranged on the same layer in the liquid crystal display device of the present invention.

9C is a plan view and a sectional view of an example in which the arrangements of the lozenge X and Y electrodes are applied to the same layer in the method of FIGS. 9A and 9B;

10 is a graph showing the change in capacitance between the X electrode and the Y electrode according to the thickness of the insulating film between the two electrodes

* Description of the symbols for the main parts of the drawings *

100 liquid crystal display 110 first substrate

120: second substrate 130: liquid crystal layer

140, 140a, 140b: polarizer

150: image signal applying unit 200: cover glass

210, 310: X electrode 211: first transparent organic insulating film

212, 312: Y electrode 220: adhesive layer

240: pad portion 241: voltage application pad

242: detection pads 251, 252: connection wiring

300: touch panel signal applying unit 411, 521: first electrode

412 and 523: second electrode 413 and 512 insulating film

421 and 511: X electrode signal application wiring

421a and 421b contact holes 431 and 525 pad electrodes

433, 522c: Pad contact hole 522a, 522b: Contact hole

Claims (12)

A liquid crystal panel including a first substrate and a second substrate facing each other, and a liquid crystal layer formed between the first and second substrates, the display area being defined at a center thereof and the non-display area being defined at an outer side thereof; A plurality of first electrodes and a second electrode formed on the liquid crystal panel and corresponding to the display area of the liquid crystal panel, the plurality of first and second electrodes which are transparent, vertically cross each other, and are electrically spaced apart from each other on a surface facing the liquid crystal panel; A cover glass having a touch sensing unit; And And a touch panel signal applying unit formed on one side of the cover glass deviating from the display area of the liquid crystal panel on the same surface as the touch sensing unit. The method of claim 1, And the cover glass is formed to protrude from the liquid crystal panel, and the touch panel signal applying unit is formed in an area of the cover glass protruding from the liquid crystal panel. The method of claim 1, And the first electrode is formed as an electrode having a long rod shape in the X-axis direction, and the second electrode is an electrode which is formed in an electrode having a long bar shape in the Y-axis direction and intersects with the X electrode. The method of claim 3, wherein And the first electrode and the second electrode are formed on different layers, and a transparent insulating film is further formed between the layers of the first electrode and the second electrode. The method of claim 4, wherein The transparent insulating film is a liquid crystal display, characterized in that formed to a thickness of 0.1 ~ 5㎛. The method of claim 1, The plurality of first electrodes and the second electrodes are formed spaced apart from each other on the cover glass, The first electrode is formed by dividing a plurality of islands in a column in a horizontal direction, And the second electrode is formed in a rod shape in one direction in a column in a vertical direction. The method of claim 6, A first electrode signal application wiring for applying a signal to the first electrodes formed in the columns in each horizontal direction is further formed on the upper side or the lower side of the first electrode via a transparent insulating film. The liquid crystal display of claim 1, wherein the liquid crystal display is electrically connected to the one electrode through a contact hole. The method of claim 7, wherein The liquid crystal panel A thin film transistor array having a gate line and a data line intersecting each other on the first substrate to define a pixel region, and a pixel electrode formed in the pixel region; And a color filter array including a black matrix layer corresponding to an area excluding the pixel area and a color filter layer corresponding to the pixel area on the second substrate. The method of claim 8, And the first electrode signal application wiring is formed corresponding to the black matrix layer. The method of claim 1, And the first electrode and the second electrode are made of one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). The method of claim 1, The touch panel signal controller is made of FPC (Flexible Printed CAble), it is folded to the lower side of the liquid crystal panel. The method of claim 1, A voltage applying pad configured to apply a voltage signal to the first electrode on the cover glass corresponding to the touch panel signal controller, the first electrode and the second electrode of the touch sensing unit being connected through a connection line; A voltage detection pad detecting a signal output from the two electrodes, And the voltage applying pad and the voltage detecting pad are connected to the touch panel signal controller by soldering.

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